CD244 Antibodies

Natural killer cell receptor 2B4 (CD244)

Heterophilic receptor of the signaling lymphocytic activation molecule (SLAM) family; its ligand is CD48. SLAM receptors triggered by homo- or heterotypic cell-cell interactions are modulating the activation and differentiation of a wide variety of immune cells and are involved in the regulation and interconnection of both innate and adaptive immune response.

Tasks are controlled by presence or absence of small cytoplasmic adapter proteins, SH2D1A/SAP and/or SH2D1B/EAT-2. Downstreaming signaling involves predominantly VAV1, and, to a lesser degree, INPP5D/SHIP1 and CBL.

Gene Information

Human
Gene Name:	CD244
Uniprot:	Q9BZW8
Entrez:	51744

Family

Belongs to:
No superfamily

Alternative Names

2B4; CD244 antigen; CD244 molecule, natural killer cell receptor 2B4; CD244; h2B4; NAIL; NAILNK cell activation-inducing ligand; natural killer cell receptor 2B4; NKR2B4; NKR2B4NK cell type I receptor protein 2B4,2B4CD244 natural killer cell receptor 2B4; Nmrk; SLAMF4; SLAMF4NK cell activation inducing ligand NAIL

Molecular Weight

Mass (kDA):
41.616 kDA

Genomic Context

Human
Location:	1q23.3
Sequence:	1; NC_000001.11 (160830160..160862892, complement)

Tissue Specificity

Expressed in spleen, PBL, followed by lung, liver, testis and small intestine. Expressed in all natural killer (NK) cells, monocytes and basophils, TCR-gamma/delta+ T-cells, monocytes, basophils, and on a subset of CD8(+) T-cells.

Subcellular Localizations

Membrane; Single-pass type I membrane protein. Cell membrane. Receptor engagement results in a recruitment to lipid drafts essential for the subsequent tyrosine phosphorylation of the ITSMs.

Diseases

• Neoplasms
• X-linked Lymphoproliferative Disorders
• Lymphoproliferative Disorders
• Infective Disorder
• Virus Diseases
• Tissue Adhesions
• Immunologic Deficiency Syndromes
• Malignant Neoplasms
• Epstein-barr Virus Infections
• Autoimmune Reaction
• Leukemia
• Hiv Infections
• Arthritis

• Rheumatoid Arthritis
• Autoimmune Diseases
• Inflammation
• Lymphoma
• Melanoma
• Hepatitis
• Malignant Paraganglionic Neoplasm

Interacting Proteins

• B2M
• CD48
• INPP5D
• PLCG1
• PTPN11

• PTPN6
• SH2D1A
• SH2D1B

Pathways

• Cell Activation
• Lymphocyte Activation
• Secretion
• Cytokine Production
• Immune Response
• Pathogenesis
• Cytolysis
• Cell Differentiation
• Cytokine Secretion
• T Cell Activation
• Cell Proliferation
• Cell Recognition
• Cell Development

• Cell Killing
• Localization
• Cell Adhesion
• Leukocyte Activation
• Interferon-gamma Secretion
• Exocytosis
• Natural Killer Cell Activation

PTMs

• Phosphorylation

• Glycosylation

• Dephosphorylation

For details, visit:
bosterbio.com/bosterbio-gene-info-cards/CD244

Best Uses Of The CD244 Marker Antibody

The best ways to use the CD244 Marker antibody are varied. Read on to learn more about how to optimize your experiments with CD244 antibodies. You will also learn how to determine whether an activating signal is present and how to optimize antibody concentration. In addition, you will learn about the limitations of CD244 antibodies. These factors will assist you in choosing the best antibody for your experiments.

CD244 antibody should only be used for its intended purpose.

The optimal use of CD244 antibody depends on how it can be applied to the target cells. CD244 is expressed at low levels by NK cells and CD8+ T cells. Low levels SAP bind the receptor, which can activate or inhibit cells. Depending on the context, the interaction between the antibody and target cells can be either inhibitory or activating. The following guidelines could be useful in optimizing CD244 antibodies.

CD244 belongs to the SLAM antigen family and shares approximately 70% identity with its mouse counterpart. Its transmembrane component contains no charged amino acids, while its cytoplasmic tail has four tyrosine-based motif, which undergoes phosphorylation. Its ligand is a glycophosphatinositol-linked molecule called CD48. It is present in all nucleated cells of the hematopoetic system.

Increased CD244 expression in the immune system is associated with increased immunosuppression. In the absence or recruitment of immune cells, the immune system will respond by depleting effector and increasing production of myeloid–derived suppressor. The immune system's resistance to current treatments is also associated with an increased expression of CD244. In the hope of achieving the ultimate goal of preventing and curing leukemia, researchers have discovered new ways to target CD244 in cancer patients.

A two-signaling mechanism is responsible for rapid CD244 internalization. This signaling mechanism is responsible in modulating antiviral CD8-dependent T cell responses. This signaling mechanism is involved in modulating the TCR-dependent downregulation of CD244. Recall that CD244 Downregulation requires simultaneous signals from both PD-1 and TCR.

The optimal use of CD244 antibody in various cancer types requires proper dosage. The antigen should be carefully selected to ensure optimal use. The antigen should be selected according to the purpose for which it is being used. It can be used to combat lymphoma tumors. The CD244 antibodies are also effective in the treatment of HIV infection.

Analysis of activating and inhibiting signals

The CD244 gene is a member a family of receptors that interacts with the SLAM transcript factor. The CD244 protein is an important member the SLAM family receptors that regulate CD4 (+) T cells as well as NK cells. Recent research has shown that CD244 plays a role in modulating the immune response to NK cells and CD8 (+) T cells. The CD244 proteins has been studied in a variety of contexts including T-cells and NK cells, as well as in latently infected individuals.

We have previously shown CD244 is associated with the cytokine range of healthy human DCs. We used BDCA1+ DCs from healthy human donor PBMCs to stimulate these cells with LPS to determine their production of cytokines. We found that crosslinking CD244 significantly inhibited LPS stimulated DCs, but not anti-inflammatory counterparts.

For intracellular staining, we used fluorescent-labeled anti-granzyme E-PE and surface-marker expression of freshly isolated cells. We were able compare the expression of SAP in healthy human lymphocytes using the same methods. Both experiments were performed using the NK92 cellular line as a guide. Each clone has been tested in duplicate.

We found a correlation of CD244 expression to the spontaneous production suppression molecules in Mo-MDSCs. Mo-MDSCs had higher levels of TGFb1, IL-10 and arginase-1, than Gr-MDSCs. CD244 expression was not correlated with the expression of IDO/PD-L1, suggesting that PD1 signaling and IDO signaling don't confound CD244.

The CD244 marker can be used to determine whether the immune system has been activated or blocked. CD244-overexpression is associated with a stronger immunosuppressive function. It has been demonstrated that CD244-/ mice are significantly more likely to develop tumors than isotype controls. These results provide additional evidence to support further investigation of immunotherapy using CD244.

The level of CD244 expression in DCs correlates with PD-1 expression in tumors. Despite low PD-L1 levels, higher levels of CD244 expression on DCs are associated to higher IFN-c or arginase-1 expression. A strong correlation has been observed between CD244 and suppressor molecule formation.

Optimization of antibody concentration

Alternative splicing is used to express the CD244 antigen in mice. There are four ITSMs and one ITSM. Human CD244 is produced by differential splicing of human RNA. Both forms share the same intracellular regions, but they differ structurally in the presence five amino acids between the immunoglobulin C2 and V domains. The shorter form exhibits enhanced affinity for CD48, and NK-cell mediated cytotoxicity (in vitro).

The signal's activating or inhibitory properties are determined by the ligation of the CD244/CD48 molecule. CD244 binding to SAP results in an inhibitory signal unless SAP is expressed in large concentrations. The ideal antibody titer depends on the SAP-CD244 ratio. The CD244-SAP signal propagates a signal with antibody, which could contribute to its activating/inhibiting effects.

Limitations in antibody titer

You can reduce the limitations of antibody titer in Boster Bio assays by increasing the dilution factors. The greater the dilution factor the lower matrix binding effects will be. Boster antibodies can only react with their target because they are affinity-purified. Boster's ELISA plate covers are coated with high-affinity antibody, which is a critical component of optimal performance. Scientists have relied on these antibodies for decades.

The same study group that received 100 ug virus was exposed to booster mRNA-1273. This resulted in a 17.3-fold increase of neutralizing titers. However, the study did not evaluate the immune response of the same individuals to the same variants. It also didn't examine the effect on the interval between booster injections. The study did not examine whether the nAb titre remained elevated or decreased following the second and third injections of mRNA-1273.

Boster Bio has some limitations to its method. First, many antibodies produced by this method may not have sufficient affinity to bind the target protein in vivo. Many antibodies may not be capable of detecting the target protein due to low levels or being masked in the matrix or in vivo. Therefore, it is not possible to validate polyclonal antibodies in clinical trials on the basis of their high titers.

Boster Bio also has limited capabilities to detect antigens which are not detected by its titer analysis. The Boster Bio assay uses microtiter plates with spike glycoproteins from the Wuhan-Hu-1 and D614G isolates and adds serum with SARS-CoV-2 IgG antibodies. Detection of the bound antigen-antibody complex was then performed by the addition of goat anti-human IgG horseradish peroxidase or purified goat anti-human IgG horseradich-peroxidase. The color developed was measured spectrophotometrically at 450 nm. The amount of human IgG antibodies to SARS-CoV-2 directly affects the intensity of the color.